Study: Tetanus, Diphtheria Boosters Not Necessary in Adulthood if Patients Were Fully Vaccinated as Children

Contrary to current CDC recommendations, a new study published in Clinical Infectious Diseases suggests that adults do not need tetanus or diphtheria boosters if they were fully vaccinated as children.¹

Tetanus is an infection spread by bacteria commonly found in dirt or feces, or on contaminated objects, such as exposed nails or needles. It causes jaw cramping, painful muscle spasms, trouble swallowing and breathing, seizures, convulsions, and sometimes death. Approximately 30 people in the United States are diagnosed with tetanus annually and up to 2 out of every 10 cases can be fatal, according to the researchers.¹

Diphtheria is another bacterial infection, which causes a thick covering in the back of the throat. This covering can result in difficulty breathing, heart failure, paralysis, or death. It is spread by exposure to infected people or, sometimes, infected animals. Fewer than 5 cases have been reported to the CDC in the last decade. Notably, about 1 in 10 cases can be fatal in an unvaccinated population, but the authors noted that more than 99.8% of vaccinated people who receive appropriate care survive the infection.¹

The new study follows data from 2016, which found that the vaccine produced at least 30 years of immunity. In 2016, the researchers concluded that vaccinations for the infections were only necessary every 30 years.¹

“Based on our new data, it turns out we were probably overly conservative back in 2016,” said lead study researcher Mark Slifka, PhD, in a statement. “Even though it looked like immunity could be maintained for decades, we didn’t have direct evidence back then that this would translate into true protection against disease in the real world.”¹

In the latest research, the authors conducted an observational cohort study using World Health Organization (WHO) case reports from 2001 to 2016. They compared the incidence of tetanus and diphtheria in 31 North American and European countries that either do or do not recommend adult booster vaccination.²

The researchers found that there was not a significant decline in tetanus incidence rates between countries that vaccinate adults every 5 to 20 years and countries that do not routinely vaccinate adults for the tetanus and/or diphtheria.²

Notably, the risk of contracting diphtheria was greater among countries that vaccinate adults due to the inclusion of Latvia, which the researchers said has poor vaccination coverage. If Latvia is excluded, however, they found no difference in diphtheria incidence.²

Based on these data, the authors concluded that there is no benefit associated with performing adult booster vaccinations against tetanus or diphtheria. The researchers estimated that requiring fewer vaccinations for adults could save the United States about $1 billion annually.²

“To be clear, this study is pro-vaccine,” Slifka said in a statement. “Everyone should get their series of tetanus and diphtheria shots when they’re children. But once they have done that, our data indicates they should be protected for life.”¹

REFERENCES

• Adults don’t need tetanus, diphtheria boosters if fully vaccinated as children, study finds [news release]. Oregon Health and Science University; February 25, 2020. https://news.ohsu.edu/2020/02/25/adults-dont-need-tetanus-diphtheria-boosters-if-fully-vaccinated-as-children-study-finds. Accessed March 11, 2020.
• Slifka A, Park B, Gao L, Slifka M, et al. Incidence of Tetanus and Diphtheria in Relation to Adult Vaccination Schedules. Clinical Infectious Diseases, published February 25, 2020. Accessed March 11, 2020.